Quick Verdict

SPY has a lower expense ratio. SPY delivered stronger 1-year returns. SPY offers more diversification with 503 holdings.

Lower Fees: SPYHigher Returns: SPYMore Diversified: SPY

Side-by-Side Comparison

MetricIDEFSPYWinner
Expense Ratio0.55%0.09%
AUM$4.2B$789.1B
Dividend Yield0.34%1.01%
Holdings131505
YTD Return+10.63%+13.79%
1Y Return+19.63%+23.66%
3Y Return (annualized)-+21.40%
5Y Return (annualized)-+13.37%
Volatility (annualized)21.6%15.3%
Max Drawdown-15.8%-56.5%
Fund FamilyiShares by BlackRock (US)State Street Investment Management
CategoryEquityEquity
InceptionMay 19, 2025Jan 22, 1993

IDEF vs SPY Performance

iShares Defense Industrials Active ETF (IDEF) is a ETF from iShares by BlackRock (US) and State Street SPDR S&P 500 ETF Trust (SPY) is a ETF from State Street Investment Management. Over the past year IDEF returned +19.63% while SPY returned +23.66%. Year to date, IDEF is up 10.63% versus a gain of 13.79% for SPY.

Risk: Volatility and Drawdowns

IDEF has been the more volatile fund, with annualized monthly volatility of 21.6% compared with 15.3% for SPY. Lower volatility generally means a smoother ride, though it often comes with lower long-run returns.

The deepest peak-to-trough decline in our data was -15.8% for IDEF and -56.5% for SPY. Drawdown depth is worth weighing if you expect to sell during market stress rather than ride it out.

The two funds' monthly returns correlate at 0.49. They move independently enough that combining them can meaningfully diversify a portfolio.

Fees and Cost Over Time

IDEF charges 0.55% per year while SPY charges 0.09%. On a $10,000 position that is $55 vs $9 annually, a gap of $46 per year that compounds over a long holding period. On income, IDEF currently yields 0.34% against 1.01% for SPY.

Holdings Overlap

3.0%overlap

IDEF and SPY share 17 holdings out of 602 unique holdings combined, representing a 3.0% weight overlap.

Moderate overlap means holding both could provide meaningful diversification benefits.

Top Shared Holdings

StockWeight in IDEFWeight in SPYDifference
LMT6.86%0.17%6.69%
BA5.12%0.29%4.83%
GD4.49%0.15%4.34%
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Frequently Asked Questions

Which is cheaper, IDEF or SPY?

IDEF has an expense ratio of 0.55% while SPY charges 0.09%. SPY is the cheaper option. On a $10,000 investment, that is $46 per year of difference.

Which performed better, IDEF or SPY?

Over the past year IDEF returned +19.63% vs +23.66% for SPY, so SPY leads on 1-year performance. Over the longest common window we track (1 years), IDEF annualized +31.83% vs +8.85% for SPY. Past performance does not guarantee future results.

Which is riskier, IDEF or SPY?

IDEF has been the more volatile fund at 21.6% annualized versus 15.3% for SPY. Worst drawdown: IDEF -15.8% vs SPY -56.5%.

Should I hold both IDEF and SPY?

IDEF and SPY have a monthly-return correlation of 0.49, so combining them can provide real diversification depending on your allocation goals.

What is the holdings overlap between IDEF and SPY?

IDEF and SPY share 17 common holdings with a 3.0% weight overlap. Combined, they hold 602 unique securities.

Which pays a higher dividend, IDEF or SPY?

IDEF yields 0.34% while SPY yields 1.01%, so SPY currently pays the higher dividend yield.

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